Improvement in stone-cutting tools



UNITED .STATEs PATENT OFFICE.

HERBERT COTTRELL, 0E NEWARK, NEW JERSEY.

IMPROVEMENT INSTONE-CUTTING TOOLS.

Specification forming part of Letters Patent No. 144,318, dated November4, 1873; application filed August 21, 1873.

To all whom "it may concern:

Be it known that I, HERBERT OoTTRELL, of Newark, Essex county, NewJersey, have invented certain Improvements in Stone-Gutting Tools, ofwhich the' following is a specification:

The tool in which my invention is comprised is designed principally tosurface rough stones, or to cut a thin layer from the stone, so as toleave a smooth surface thereon. The cutter proper is a revolvingcircular disk, armed on its periphery with carbons or diamonds, whichconstitute the cutting-edge. With the revolving circular cutter iscombined a stationary wedge or beveled disk, which lies on the upper orouter face of the circular cutter, with its periphery at a properdistance from the cutting-edge, and serves, when the tool is fed againstthe. stone, or vice versa, as a wedge to break off the portion of thestone left above or outside of the kerf cut by the diamond edge of thecutter. feature of my invention consists in this combination of arevolving circular diamondarmed cutter and a stationary wedge or beveleddisk, the principal advantage derived being that, inasmuch as thewedge-disk, which forms part of the tool, is stationary, it is not actedon so injuriously by the grit of the stone, and is not rapidly worn outand ground away, as it would be were it to revolve with the cutter.

The nature of my invention, and the manner in which the same is or maybe carried into effect, will be readily understood by reference to theaccompanying drawing, in which Figure 1 is a perspective view of a toolmade in accordance with my invention, and Fig. 2 is a longitudinalvertical section of the same.

The cutter proper consists of a circular metallic disk, A, armed on itsperiphery with carbons or diamonds, contained and held in steel sectionsa in the usual way, so as to 0011- stitute a cutting'edge. This disk isfixed to a revolving spindle designed to be supported in suitablebearings, and to be rotated at a high velocity. The disk can be securedto the spindle by being keyed thereto; or, what is preferable, it may beprovided with a screw- The essenti althreaded hub, engaging and fittingthe corre spondingly screw-threaded end of the spindle. The cutter-diskis also preferably made concave, as shown; since, with that form, it canmore readily clear itself, and more freely admit the supply of water. Tothe outer face of the revolving cutter is applied the wedge or beveleddisk 0, which is fixed to and supported by a hub fast to the frontbearing of the spindle B. This wedgedisk is, consequently, stationary.It is made of metal, and is in contact, or very nearly so, with thecutter. It tapers or is beveled in such manner that its exterior edge orperiphery is of little thickness, and does not project so as to havemore thickness than the kerf cut by the diamondcdged cutter. It will beunderstood that the tool can be either fed against the stone or thestone can be fed against the tool, as is customary in like cases.

The operation is as follows: The diamondarmed sections attached to theperiphery of the revolving circular cutter-disk cut into the stone, thekerf being made by the carbons or diamonds held in said sections.Further progress forces the stationary beveled disk into the kerf, andthis disk operates as a wedge to divide the stone by breaking off theportion left above or outside the kerf. Thus, in surfacing stone, but asmall portion is ground to powder, the bulk of the rough portion being,by the action of the wedge-disk, thrown off in the form of chips. Thiswedge-disk, being stationary, is not rapidly ground and worn away anddestroyed, as it inevitably would be were it to revolve with the cutter.

What I claim, and desire to secure by Letters Patent, is

The combination of a revolving diamond or carbon armed circular cutterand a stationary wedge or beveled disk applied to and operatingin-connection with said cutter, substantially as hereinbefore described.

In testimony whereof I have hereunto signed my name in the presence oftwo subscribing witnesses.

HERBERT COTTRELL. Witnesses:

IRA M. TAYLOR, LUGIAN H. WEEKs.

